Molinism, and the Grounding Objection
The question of how to reconcile God’s foreknowledge and human free will has plagued theologians for centuries. A view called Molinism presents itself as a logical explanation of how the two can be reconciled.
The major objection to Molinism is known as the “grounding objection”, and in my opinion it disproves Molinism completely. The grounding objection is the observation that the idea of (libertarian) free will means that people’s decisions can’t be known with certainty before they’re made, but Molinism claims God foreknows them.
Put a little more formally, it looks like this:
A. God foreknows the things he foreknows because they are true. He doesn’t just guess. There is an actual causal connection between something being true and God gaining foreknowledge of it. ie his foreknowledge is causally dependent on the truth of the thing he foreknows. (from definition of Exhaustive Definite Foreknowledge)
B. The truth of X depends on the person’s decision to do X. ie the person’s decision causes the action. (from definition of Libertarian Free Will)
Conclusion 1. Hence God’s foreknowledge is causally dependent on the person’s decision. (from A & B)
D. The person’s decision is indeterministic. (from definition of Libertarian Free Will)
E. The outcome of an indeterministic event cannot be calculated or predicted in advance even if everything is known about the situation and causes of the event. (from definition of Indeterminism)
Conclusion 2. The person’s decision cannot be calculated or predicted in prior to the person making it. (from D & E)
Conclusion 3. God cannot have foreknowledge of the decision prior to the person making it. (from conclusions 1 & 2)
This shows that is logically impossible for God to have definite foreknowledge of libertarian free will decisions. It is very rare in philosophy to get such a clear argument, so this is one of my favorites.
This means that either:
1. God’s foreknowledge is limited to some degree (ie the Open View); or
2. That free will is compatibilist not libertarian.
Of course a person can endorse both 1 and 2 if they wanted. However if Christian rejects Open Theism then, per the grounding objection, they logically ought to endorse 2. But endorsing Compatibilism and rejecting Open Theism seems to inevitably end up affirming double-predestination. So it seems to me that Christians really have a choice between Open Theism and double-predestination.